A test tube of mass 10 g is closed with cork of mass 1 g. The test tube is filled with ether. When it is heated, the cork flies out as a result of pressure of the ether. The test tube is suspended horizontally with a weightless bar of length 5 cm. What is the minimum velocity with which the cork must fly to describe a full circle vertically about the point O. Neglect the mass of ether.